Interlocking relay



June 11, 1940. J EVANS AL 2,203,779

INTERLOCKING RELAY Filed Sept. 25, 1956 4 Sheets-Sheet 1 INVENTOR.

JAMES M. EVANS EDMUND J. PHILLIPS ATTQRNEYS June 11, 1940. J EVANS ET AL2,203,779

I N TERLO CK ING RELAY Filed Sept. 25, 1 936 4 Sheets-Sheet 2 FIG.2'. I

ZNVENTOR. JAMES M. EVANS EDMUND J. PHILLIPS zmm. ATTORNEYS.

June 11, 1940. J. M. EVANS ET AL 2,203,779

mmnmcxme RELAY Filed Sept. 25, 1936 4 Sheets-Sheet 3 INVENT Fi o iie 21mGJ BY M,EM17,M 7116414 A TTORNE rs June 11, 1940. J M EVANS r AL2,203,779

INTERLOCKING RELAY Filed Sept. 25, 1936 4 Sheets-Sheet 4 JL u g 2 lL 0 IJ I: m" 1 8 g O INVENTOR JAMES M. EVANS y EDMUND J. PHILLIPS M4 MfmPatented June 11, 1940 UNITED STATES PATENT OFFICE INTERLOCKING RELAYJames Moore Evans and Edmund J. Phillips, Detroit, Mich, assignors toEvans Products Company, Detroit, Mich., a corporation of DelawareApplication September 25, 1936, Serial No. 102,460

6 Claims.

It has been customary, heretofore, in connection with rail-highwaycrossings, to cause the approach of a train to the crossingfrom eitherdirection to actuate the crossing signal devices when the approachingtrain reaches a point a substantial distance in advance of the crossing,and maintain the signal in operation until the train reaches andslightly passes the crossing. conventionally, this is accomplished bydividing the railway adjacent to the crossing into two signalingsections, the junction between which is located at the crossing, andeach of which sections extend a substantial distance in acorrcspondingdirection from the crossing. A relay and a source ofcurrent are provided at each section. The entrance of the train intoeither section actuates the relay associated therewith, which actionplaces the crossing signal. or signals in operation. The departure ofthe train from the section restores the track relay to its originalcondition, extinguishing the signal. In order to prevent the signalingdevices from being maintained in operation as long as the train is inthe out-going section, electrical and mechanical in ter loclc ng hasbeen employed to cause the operation of the relay associated with theoncoming section to lock out the relay for the out-going section.

In cases Where the crossing to be protected is relatively wide, it oftenhas been found desirable to provide three separate signaling sectionsfor each crossing, one of which extends from a point a short distancefrom one side of the crossing to a point corresponding distance from theother side of the crossing, and the other two of which extend inopposite directions from the respective ends of the central or crossingsection. In using the three separate sections, it is desirable that atrain approaching a crossing from either direction he eliective toactuate the crossing sig nals upon entering the approach section fromthe corresponding direction, and to maintain the signals in. operationuntil it has passed completely out of the central or'crossing section.It is furthcr desirable that inter locking be provided so that a trainis ineffective to actuate the signals during its passage through theout-going approach section.

It frequently occurs that a highway or other road crosses the railroadat or near the location of a rail turn-out or siding. In such instances,a train coming on to the main track by way of the siding or turn-outwill reach the main track at a point included within the central orhighway section. In such instances, it is desirable that the approach ofthe train on the turnout be effective to actuate the signals andmaintain them in operation until the train passes out of the central orhighway section. It is desirable also that inter-locking be provided toprevent the operation of the signals during the time that the train ispassing through the approach section on the out-going side.

With the foregoing and other considerations in view, objects of thepresent invention are to provide a crossing control system embodying acentral or crossing section, and one or more ap proach sectionsextending from the respectively opposite ends of the central section,and so ar-- ranged that the entrance of a train or other vehicle intoeither approach section is effective to actuate the crossing signaldevices and to maintain such devices in operation until the ve-- hiclepasses through the central section; to provide such a system so arrangedthat the signaling devices are extinguished when the vehicle passes outof the central section, and are not operative during the time thevehicle is passing through the approach section at the out-going side ofthe crossing; to provide such a system so arranged that the just statedoperation is efiectecl independently of the direction from which thecrossing is approached; to provide such a system embodying relaymechanisms individual to the respective approach sections and t0 thecentral section, and including means for inter-locking such relaymechanisms; and to provide such an arrangement embodying means formechanically inter-locking the respective relay mechanisms.

Further objects of the present invention are to provide a crossingprotective system of the above stated character, embodying means forinterlocking the relay mechanisms for the respective sections in such away that a vehicle entering the central section inter-locks and preventsoperation of the relay mechanisms for both of the approach sections,which inter-locking remains effective as long as the vehicle is in anyof the sections associated with the crossing.

Further objects of the present invention are to provide, for use in acrossing protective control system of the above stated character or thelike. an improved inter-locking relay structure em bodying three sets ofoperating coils, contact Ill) controlling miniatures individual thereto,and mechanical interlocking mechanism ed between the res cctivearmatures; and to provide such a structure in which the inter cokinginech-- anism may be added to existing inter-locking structures.

With the above and other objects in view which appear in the followingdescription and in tle appended claims, preferred but illustrativeembodiments of the present invention are shown in the accompanyingdrawings, throughout the several views of which corresponding referenceci "acters are used to designate corresponding parts, and in which:

Figure 1 is a view in front elevation of a pre ferred construction ofone embodiment oi a three element inter-locking relay of the presentinvention;

Fig. 2 is a view in front elevation taken along the lines 2-2 of Fig. 1;

Fig. 3 is a fragmentary view in perspective, illustrating furtherdetails of the inter-lockini mechanism of the structures of F l and 2;

Fig. 4 is fragmentary View in perspective of a modified adaptation of anembodiment of the invention;

Figs. 5 through 11, inclusive. are comparative views illustratingvarious operating positions of the inter-locking mechanism of the relaystructure shown in Fig. 4;

Fig. 12 is schematic diagram of a control system embodying theinvention.

Referring first to Figs. 1, 2 and 3v the relay there shown is of thethree element inter-locking type, based upon the arrangement shown inLockhart Patent No. 1,799,629, granted April '7, i931. and isillustrated embodying three opersting coils, A, B, C, carried upon aninsulating support 29. Although only three operatin'. coils are shown,for convenience. it will be apprec ated that each coil may be replacedby a set of two or three coils operatin upon the same armature. Thecores 22, 24 and 28 of coils A, B and C extenc through the supportingmember 20, and

terminate in enlarged pole pieces 33 and 32,

respectively.

The coil A controls an armature 34, pivotally connected thereto by a pin35, carried by the pole piece 28. Armature 34 is provided with an armremovably secured thereto, which carries a contact carrying finger All.In the positions of the parts illustrated in Fig. 2, the contact 52carried at the end of finger is in engagement with a stationary frontcontact member 44, which is supported from the member 20. and iselectrically connected. to a conventional terminal 45. Except asinfluenced by the hereinafter described inter-locking mechanism,de-energizm tion of coil A permits finger 4 to rotate by gra. ity in acounter-clockwise direction as viewed in Fig. 2, to a position in whichthe contact point. 22 engages stationary back contact point 48, in turncarried by the supporting member 20 and electrically connected to ausual terminal It will be appreciated that coil A may be provided withadditional moving and stationary contact points, dependent upon thesignal requirements of the system with which the relay is associated,the illustrated contacts being suffic ent to show the adaptation of therelay to the control of both front and back contacts. Coils B and C areprovided with moving and stationary contacts which correspond in allrespects to those associated with coil A, the upper stationary frontcontacts for coils B and C being designated 52 and 54, respectively; thelower stationary back contacts for these coils being designatedrespectively 56 and 58; and the moving contact points being designatedas 60 and B2, respectively. 1

To eliect the inter-locking action, the armature 34, 38 and areprovided. with extensions 64, 55 and 68, respectively, which are in turnprovided with resilient fingers l0, l2 and "i4. Fingers l0, l2 and 74are biased. to the illustrated positions, parallel with the arinatiu'eextensions, by oppositely disposed members associated there-- with andconnected to the associated armature extension. The members associatedwith finger T0 are designated i5 and ":8, member l8 bearing upon the topoi finger "i l and member '38 bearing upwardly upon the bottom of fingerT9. The members for the other fingers are similarly c0nstructed andarranged.

The armature extensions 64 and 58, associated with the electro-magnets Aand C, respectively, are provided with relatively resilient fingers and82, respectively, the outer ends of which are downwardly bent to provideshoulders 85 and 8G. Arms 88 and 90, of somewhat heavier metal, aredisposed immediately below the resilient fingers 8t and 82, to limit thedownward movement thereof relative to the associated armatureextensions, and to also support the associated arniatures, ashereinafter described.

The mechanism ior interconnecting the various interlocking elementscomprises the two members 92 and 94, which are pivotally supported ontrunnions 96, 98 and H10. which are carried in U-shaped brackets H32,H34. NS. The brackets are directly supported by the relay supportingmember 729. l iember .2 is provided at one end with an. upstandingfinger H0, which normally lies below and in slightly spaced relation tothe shoulder 84 formed at the end of the resilient finger 83; anoperating finger H2, which normally lies below and. in spaced relationto the resilient finger l2; and a second operating finger H4, whi hnormally lies below and in spaced relation to the resilient finger 14.One or more counter-weights, such as US, are preferably provided to biasmemb r 92 to the illustrated position. Stops such as l l! limit angularmovements of member The other connecting member, 94, is provided with anupstanding finger I20, corresponding to finger H0, and disposed incorresponding relation to the shoulder 86 of the resilient finger G2;and is also provided with operating fingers 122 and I24, correspondingto the operating fingers H2 and H4, and correspondin-ly related tofingers Hi and 72. It is noted that finger T2 is broad enough to spanboth of the operating members H2 and I22. Member 84 is also providedwith counterweights s ch as I26 to bias it to the illustrated position,and with steps, such as H! for member 92, to limit angular movements.

In on ration, the coils A, B and C are normally ed and so maintain thearmatures 34, 36 and in the positions illustrated in the variousfigures, in which posi ions the moving contacts 42, and G2 engage theupper stationary front contacts 44, 52 and 54, respectively. In thenormal positions of the parts also, the two fingers 3C and B2 aredisposed slightly above the interlocking fingers H0 and I20,respectively, and the int r-locking fingers HE, l2 and [4 lie above andin spaced relation to the operating fingers 924, {12,522 and H4.

Assuming, for example, that the electro-magnet A is de-energized, thearmature 34 thereof falls by gravity in a counter-clockwise direction asviewed in Figs. 2 and 3, during the course of which movement the movingcontact 42 tends to be moved out of engagement with the upper stationarycontact 44. In certain instances, it is desirable to so arrange thecontact structure that even a slight initial movement of the armature issufficient to move the moving contact away from the stationary contact44. In certain other instances, such for example, as in the hereinafterdescribed control system, it is preferred to utilize contacts of theso-called flagman type, that is, contacts so arranged that a substantialinitial amount of movement of the armature is required to move themoving contact 42 away from the stationary contact 44. Specifically, itis preferred to so arrange the construction that the moving contact 42remains in engagement with the stationary contacts 44 unless thearmature moves farther than the hereinafter described mid-position, asprovided by the inter-locking mechanism. This may be accomplished, aswill be appreciated, by forming the contact finger 40 of resilient material and arranging it so that in the illustrated position of theparts, the finger 40 is stressed somewhat. In the instance beingassumed, armature 34 falls to its lowest position, bringing contact 42into engagement with contact 48.

Continuing the operation resulting from a deenergization of theelectro-magnet A, the downward movement of the armature 34 thereofbrings the finger 10 into engagement with the operating finger I24associated with member 94, and rotates the latter member in a clockwisedirection as viewed in Fig. 3, to a position in which the upper end ofthe finger I 20 lies behind the shoulder 86, and beneath and in spacedrelation to the outer end of the supporting finger 90. During thedownward movement of the armature 34 of electromagnet A, the shoulder 84of finger 8i! bears upon the upper end of the finger II 0, which action,however, due to the light construction of finger 80, does not interruptthe downward armature movement. With the parts in the just statedposition, it is believed to be evident that the armature 38 ismechanicelly locked against movement to the lower position, since, uponde-energization of the electromagnet C, the finger 90 which, aspreviously stated, is heavy enough to maintain the armature 38 in theupper position, moves downwardly upon and is supported directly by theupstanding finger I20. The only effect of a de-energization of theelectro-magnet C under the just stated conditions, is to permit itsarmature to fall to the mid-position, in which the shoulder 86 lies infront of the hook shaped end of the finger I20.

Assuming now that the electro-magnet A is re-energized, the armature 34thereof is drawn upwardly, moving the finger I0 upwardly out ofengagement with the operating finger I24. In response to this action,due to the counter weight I26, the connecting member 94 tends to rotatein a counter-clockwise direction as viewed in Figs. 2 and 3, to relievethe finger I20 from the fingers 85 and 32. This action is, however,prevented by the shoulder 86, unless the electromagnet C is energized.In the latter event, shoulder 86 is raised above the level of the end offinger I20, permitting the latter to move out \vardly therefrom into theinitial illustrated position.

It will be seen, therefore, that a de-energization of electro-magnet Aduring the energized condition of electro-magnet C, applies a mechanicallock to the armature of electro-magnet C, which mechanical look, whilepermitting movement of the armature 38 to an intermediate position,prevents movement thereof to the lower position. It will also be seenthat the mechanical lock thus applied is rendered inefiective upon there-energization of the electro-magnet A, only in the event that theelectro-magnet C is energized. It is believed to be evident, in view ofthe similar relation which exists between the armatures 34 and 38, thata de-energization of electro-magnet C during the energized condition ofelectromagnet A, imposes a mechanical look upon the armature 34whichduplicates in all respects the just described mechanical lock forarmature 38.

In view of the fact that the armature 36 associated with theelectro-magnet B is not provided with the locking member correspondingto fingers 84 and B0 of armature 34 and fingers 82 and 90 of armature38, the armature 36 is free to move to its lower position independentlyof the energized or de-energized condition of the electromagnets A andC. Movement of armature 36 to the de-energized position, however,imposes the just described mechanical lock to both armatures 34 and 38,independently of whether these armatures are in the energized orde-energized position at the time that the de-energization ofelectro-magnet C occurs. Assuming, for example that the parts are in thenormally energized position shown in the figures, a de-energization ofelectro-magnet B permits armature 36 to fall to its lower position,during the course of which movement finger I2 engages both of theoperating fingers H2 and I22, consequently rotating both locking members92 and 94 in the clockwise direction as viewed in Figs. 2 and 3. Theseactions lock both the armatures 34 and 38 against movement to the lowestpositions thereof, in the manner described above. If, during the deenergized condition of electro-magnet B, either or both ofelectro-magnets A and C are de-energized, the armatures thereof fall tothe intermediate positions, in which positions they are retained by theengagement between the sup porting fingers 88 and 90 thereof with thefingers I III and I20, respectively. In the last mentioned positionsalso the shoulders 34 and 86, respectively, overlie the hook shaped endsof the fingers II 0 and I20 and provide locks which prevent members 92and 94 from rotating to the unlocked position, even though theelectro-magnet B is re-energized. The unlocking of electro-magnets A andC may, therefore, be accomplished only by energizing both such magnets.If the de-energization of electro-magnet B occurs at a time when eitherelectro-magnets .A or C is de-energized, the locking action is the sameas just described since in this instance the fingers III] and I20 may beswung under the fingers 80 and 82, respectively, even though fingers tiland 82 may be bearing thereon.

In the modified arrangement of Fig. 4, the electro-magnets A, B and Care provided with armatures 34, 36 and 38 corresponding in all respectsto the previously described armatures and which armatures may also beprovided with correspondingly constructed and arranged moving andstationary contacts. The moving and stationary contacts are not shown inthe drawings in order to simplify them. The inter-locking structurebetween the armatures 34 and 38 of Fig, 4 is similar in many respects tothat disclosed in Patent No. 1,824,131, granted September 22,

1931, to O. 8. Field, and comprises generally a pair of hell crankmembers E and IE2, provided with hook shaped ends I34, #35,respectively, and pivotally connected. as by pins I38 and I40 to asupporting member I32 which may be formed integrally with or suitablysecured to the sup- 130i 'ing structure for the The bell crank membersI36 and l32 are provided with counterweight-s W3 and M5, which bear uponand are supported by member I48 wiich is stationary with respect to themember M2, and also acts to provide a support for the outer ends of thepins 538 and M6. As will be appreciated, the counler-weights M4 and M6urge the ends I34 and 536 or" the bell cranks away from each other tothe positions illustrated in the figure. The bell cranks I39 and 132 areprovided with shoulders I50 and E2, respectively, which normally liebelow and in spaced relation to the outer ends of operating fingers 554and which are directly connected to the armatures 34 and 3B.

The just described elements eliect an interlocking between tie armaturesassociated with clectro-megnet A and C which is functionally equivalentto that provided in the previously described enibodiment, in the mannerdescribed in the above identified Field patent. As described A d ringduring the ere-energized condition of electronisgnct A, permits theoperating arm I56 to move into engagement with the shoulder I52 of bellcrank F32, tending to rotate the latter in a clockwise direction asviewed in Fig. 4. The rotation thus produced is interrupted at anintermediate point in the downward movement of the armature ofclectro-magnet C, by the engagement of the lower end of hell crank I32with. the under-side of lower end of bell crank I30. In the limitposition thus provided. the hook I38 at the end of cell crank I32 liesbehind and below the lower end of bell crank I30.

Assuming now that electro-magnet A is reenergizcd, the armature 34thereof lifts the operating arm 55% out of engagement with the shoulder553 or bell crank I38. The counterweight associated with bell crank I30tends to re" e the later in a clockwise direction to restore it to thposition illustrated in Fig. i. Such rotation is, ..owever, prevented bythe just mentioned hook 535. The parts thus remain in position to lockthe armature 33 of electro-magnot C, until such time as electro-magnet Cis recnerpzed to lift member I58 away from bell crank 32 and permit it,as well as hell crank n t block bell crank Hi and the the end of hellcrank I30 becomes prevent a return movement of hell crank H12.

in accordance with the present invention, in

order to render electronnagnet 15 effective to lock out both ofelectro-magnets A and C, the armature SE of electro-maget B is providedwith a finger Ififl, which normally lies above and in slightly spacedrelation to one end of a bell crank Bell crank I62 is pivotallyconnected, as by a pin 64, to a bifurcated member 166 which may beformed integrally with or suitably secured to the relay supportingstructure. The outer and upwardly turned end I68 of hell crank IE7! isprovided with an oppositely shouldered in- I1er-locl-2ing tip HQ. Thetip IIfi is disposed, upon de-energiza ion of the armature 36, to bemoved upwardly between the bell cranks I30 and 5-32, to thereby forr astop to limit movements tl' ereci, and lock the same in the intermediatepositions.

typical operating sequence of the complete structure of Fig. 4 is shownin the comparative views, Figs. 5 to 9. In Fig. 5, both of the operatingarms I54 and IE5 are in their normal upper positions, corresponding toan energized condition of both electro-magnets A and C, and theshouldered tip I'IG is in. its normal lower position, corresponding toan energized condition of the electro-magnet B. Assuming that theelectromagnet A is "re-energized, the arm I54 falls to the lowerposition shown in Fig. 6, rotating the bell crank 53 in thecounter-clockwise direction to the position shown in Fig. 6, in whichposition. previously described, it is eliective to block movement ofbell crank I32, and so limit a downward movement of the armatureassociated with electro-magnet C to a halfway point.

Assuming now that during the de-energized condition of electro-magnet A,electro-magnet B is tie-energised, the parts assume the positions shownin Fig. 7, in which the shouldered tip I70 lies in blocking relation tothe end of bell crank I32, and is also effective to prevent a returnmovemcnt of hell crank I39 to the original unlocked position. Thus. aslong as electro-magnet B is tie-energized, tie energized or de-energizedcondition of electro-magnot A is immaterial, so far as concerns thelooking out of the armature associatcd with electro-magnet C.

Assuming further that the electro-magnet C is now die-energized, theparts assume the positions shown in Fig. 8, in which the hook I35 formedat the lower end of hell crank I32 is inter-locked with a correspondingshoulder of tip I10 and so retains both tip I!!! and bell crank I351 inthe locking position. Thus, assuming a prior de-energization of eitherelectro-magnet A or electromagnet B, and a de-energization ofelectro-magnet C, prior to the re-cnergization of electromagnet A orelectro-magnet B as the case may be, or both, the armatures ofelectro-magnets A or B, or both, remain locked until such a timeelectro-magnet C is again re-energized. 9 illustrates the relation thata re-energization of electro-magnet A does not release either bell crankI30 or tip I70 from bell crank I32.

The remaining two figures, I0 and II, illustrate, as will be evident,that an initial de-energization of electro-magnet B projects tip I I0into the space between bell cranks I30 and I32 and looks out thearmatures associated with both electro-magnets A and C. Also as shown inFig. 11, a de-energization of either electro-magnet A or electromagnet Cduring the de-energized condition of electro-niagnet B, prevents eitherelectro-magnet A or electro-magnet C from being unlocked even thoughelectro-magnet B is reenergized, until such time as both electro-magnetA and electro-rnagnet C are again r-energized.

It is believed to be evident from the foregoing that the inter lockingbetween the armatures associated with the respective electro-magnets A,B and C, utilizing either the inter-locking mechanism of Figs. 1, 2 or3, or that of Fig. 4, may be utilized in a wide variety of signalingsituations. Two typical situations are those outlined generally in theforepart of the present specification.

In one of these, the electro-magnet B is associated with the centralsection at an intersection to be protected, and the electro-magnets Aand C are associated with approach sections at either side of theintersection. A vehicle in passing the crossing, therefore, sequentiallyde-energizes the electro-magnets either in the order A, B, C, or in thereverse order, depending upon the direction of travel of the vehicle.The re-energization of the electro-magnets occurs in the same relativeorder as the de-energization thereof. Where the vehicle is longer thanthe central section, a period occurs during each passage during whichall three alectro-magnets are de-energized. Where the vehicle is shorterthan the length of the central section, the re-energization of theelectro-magnet associated with the approach section on the oncoming sideis always reenergized prior to the deenergization of the electro-magnetassociated with the approach section on the out-going side. In eitherinstance, the resultant operation is such that the signals or otherdevices associated with the crossing are actuated when the vehicleenters the approach section on the incoming side; re-

mains in the actuated state until the vehicle passes completely out ofthe central section, at which time they are restored to their originalposition; and are prevented from operation by the inter lockingmechanism during the passage of the vehicle through the approach sectionon the outgoing side.

The second previously mentioned illustrative situation is one in which,in connection with railways, a siding is associated with the main track,which siding enters the main track at a point within the centralsection. In such cases, trains coming into the main track by way of thesiding first de-energize the electro-magnet B associated with thecentral section and thereafter de-energize the electro-magnets A or Cassociated with the approach section on the outgoing side.Alternatively, a train entering by way of one of the approach sectionsand turning off on the siding first de-energizes the electro-magnet forthe approach section on the oncoming side and thereafter de-energizesthe electro-magnet for the control section. In the one case the signalsare actuated to signaling condition as the train enters the centralsection by way of the siding, and are extinguished at the time the trainpasses out of such a section. In the other case, the signals areactuated at the time the train enters the approach section on theoncoming side and remain actuated until the train passes completelythrough the central section.

Referring now to Fig. 12, the tracks I80 and l'82 of an illustrativerailway are divided by conventional rail joints (1, b, c and d intothree sections ab; bc; and cd. Section b--c extends through theintersection betweenthe railway and an illustrative highway or otherroadway H; the section a-b extends in one direction from the crossingfrom the central section, and the remaining section c-d extends in theother direction from the crossing adjacent the central section. Therespective sections are provided with conventional sources of trackcircuit ener y, individual thereto, illustrated as comprising battriesBl, B2 and B3, connected across the two rails adjacent one end of theassociated section. It will be appreciated that if desired alternatingcurrent sources of track circuit energy may be used. The electro-magnetsA, B and C of the previously described inter-locking relays areconnected across the rails of the respective sections. As illustrated,electro-magnet A is connected across the rails of section ab;electro-magnet B is connected across the rails of section b-c; andelectro-magnet C is connected across the rails of block c-d.

In order to illustrate the adaptability of the present invention tosignaling systems of both the normally open and the normally closedtype, circuits are shown utilizing both normally open and normallyclosed relay contacts. The front or normally open contacts aredesignated AI BI and Cl, and these contacts remain closed as long as theassociated coils are energized. Contacts Al and CI are of the previouslyidentified fiagman type, that is, are adapted to remain closed exceptupon movement of the associated armature to the full de-energizedposition. The remaining contacts are designated as A2, B2 and C2,respectively, and these contacts, as will be appreciated, are openexcept when the associated coil is deenergized, and the associatedarmature is in the lowest or unlocked position.

As will be appreciated, the signaling and other elements responsive tothe respective relay contacts, may be arranged in various ways, and maybe of either the audible or visual type. They may also be of the barriertype shown in the Goodman Patent No. 1,378,234, granted September 18,1932. The particular nature and arrangement of the signaling devicesresponsive to the respective relay contacts, form no part of the presentinvention, and have been illustrated simply as control relays designatedas XR and XRI.

In operation, it will be appreciated that as long as no vehicleeffective to shunt the tracks occupies any of the above describedsignaling sections, the respective coils A, B and C are all energizedfrom their associated batteries, and maintain the contacts individualthereto in the positions illustrated in 12. Under such conditions, therelay coil XR remains continuously energized. Coil XRI, on the otherhand, remains Lie-energized since the circuits provided therefor areopen at the parallel connected contacts A2, B2 and C2.

Assuming, for example, that a vehicle enters the section a --b, theshunt circuit between the the two rails I80 and I82 provided, forexample, through the Wheels and axles thereof, so far deenergizes thecoil A as to permit the armature associated therewith to fall to thetie-energized position, opening the contact Al and closing the contactAZ. This action de-energizes the relay XR and energizes the relay XRI,which correspondingly effect the associated desired signal or controlfunctions.

The de-energization of the electro-magnet A also applies the previouslydescribed mechanical lock to the armature of the electro-magnet C, thislook being applied either through the structure shown in Figs. 1 through3, or the structure shown in Figs. 4 through 10, but does not apply aninter-lock to the armature of electro-magnet B.

As the train or other vehicle progresses towards the highwayintersection, it passes into the section bc, and correspondinglyde-energizes the electro-magnet B, the contact Bi of whichcorrespondingly opens and the contact B2 of which correspondinglycloses. These actions are without immediate effect in view of theprevious eenergization of the electro-magnet A. Similarly, the droppingof the armature of electro-magnet B due to the de-energiaation thereofdoes not modify the mechanical lock previously applied to the armatureof electro-magnet C by the dropping of the armature of the electromagnetA.

the vehicle continues along the track, and enters section c d, theelectro-niagnet C is deenergized, and the armature thereof tends to fallto the lowest position thereof, but is prevented from falling past theso-called half-way point by the mechanical lock initially appliedthereto by electro-niagnet A. The contact C2, therefore, remains open,and the contact Cl remains closed. The de-energizaticn of electro-magnetC, however, does render it effective to self-lock itself, as previouslydescribed.

As the trailing end of the vehicle passes out of section cb,electro-magnet A is re-energized, resulting in a re-closure of thecontact Al, and a re-opening of the contact A2. These actions arewithout effect, in View of the now closed condition of contact B2, andthe now open position of contact Bi. The return of the armature ofelectro-magnet A to unlocking position also is without effect upon thelocked condition of the armature associated with electro-magnet C, sinceelectro-magnet B is now in the ale-energized or looking position, andalso because of the self-lock applied to electro-magnet C by thede-energization thereof.

As the trailing end of the vehicle passes out of section bc,electro-magnet B is re-energized, recloses contact Bi and re-openscontact B2. These actions rc-energize relay XR, and de-energize relayXRl, thus restoring the signaling devices and KR! to the initialcondition. The re-energization of eleotro-rnagnet B does not, however,unlocl: the armature of electro-magnet C, the locking relation beingmaintained in the structure of Figs. 1 through 3 by the shoulder 86associated with the finger 82 of electro-magnet C and in the case of thestructure of Figs. 4 through 10, by the hook I36 associated with thebell crank 32. As long, accordingly, as the vehicle remains withinsection c-d, the armature of electro-rnagnet C remains in the lockedcondition in which it is ineffective to open the contact C! or close thecontact C2.

It will be appreciated, therefore, that in a continuous passage of avehicle through the three sections, in succession, in the manner justdescribed, the signaling elements and KR are actuated to signalingcondition upon the entrance of the vehicle into the initial section;remain in signaling condition during the passage of the vehicle throughthe initial section and through the central or highway section; and arerestored to non-signaling condition upon the departure of the vehiclefrom the central or highway section.

It is believed to be evident that an operation duplicating the justdescribed operation occurs in the event the vehicle travels in thedirection opposite to that just described, in which event theelectro-magnet A is mechanically locked out.

In certain instances, as stated, it may be exected that the leng h ofthe central or highway ection b-c will exceed the length of the vehiclewhich is traversing the railway, in which event there is an intermediateperiod. during the passage of the vehicle past the intersection duringwhich period only the electro-magnet B is de-energized. In such cases,the operation remains the same as described above, since as previouslystated, electro-magnet B is effective to lock out both of theelectro-magnets A and C, so that the re-energization of electro-magnet Aor C, as the case may be, as the vehicle leaves the entering section andlies wholly within the central highway section, does not unlock thepreviously locked electro-magnet.

As also shown in Fig. 12, a rail turnout comprising the two rails 184and 138 joins the two main rails I86 and l82 at a point lying within thecentral or highway section b-c. With this situation, it will beappreciated that vehicles coming on to the main "ac-k by way of theturnout rails, do so without passing through either entering section.

The rail turnout may be insulated and bonded in any one of a variety ofconventional ways, since the particular details of the bonding andinsulating form no part of the present invention. As illustrated,however, insulated rail joints f isolate the turnout rails I84 and 185from the balance of the turnout and are positioned, in accordance withconventional practice, at at least fouling distance from the junctionbetween the main and turnout rails. desired, of course, the joints I maybe positioned farther from the crossing than the fouling distance by anamount determined in accordance with the expected speeds of vehicles onth turnout rails. Additional insulating joints 6 are interposed in theturnout rails adjacent the junction between these rails and the mainrails in order to prevent short circuiting of the crossing section bc. Acrossconnector I88 is connected between the turnout rail 84 and the mainrail 82. An equivalent cross-connection between the turnout rail 185 andthe main rail (39 is aiforded by the usual frog I90. The switch points192 and i! are mechanically connected by a member I96, but are insulatedfrom each other by a joint 9. A juniper N38 is placed around the switchpoint 592, in accordance with conventional practice.

It will be appreciated that the just described rail turnout connectionsdo not interfere with the previously described s quence of operation inthe event 0! through travel along the tracks I80 and If a vehicleapproaches on the turnout rails, and passes the rail joints f, ashunting circuit for electromagnet B is completed, which extends fromthe main rail lBO through the frog, I90 to the turnout rail H36, thencethrough the vehicle Wheels and axles to the turnout rail !84, andthrough the cross-connection Hi8 to the other main rail I82. The shuntthus provided de-energizes electro-magnet B. causing the contact B! toopen and the contact B2 to close. Contact B! de-energizes the relay XRand the contact B2 energizes relay XRI, which relays function. aspreviously described. to effect the desired control or signaloperations. A vehicle entering the section b-c by way of the turnoutrails I84 and I86 thus actuates the signals in the some way as would avehicle entering either of the approach sections dc or c-d.

De-energization of the electro-rnagnet B. in addition to actuating thesignal equipment. including the relays XR and XRl as just described,also mechanically locks both of the electro-magnets A and B in themanner previously described in connection with the relays.

As the vehicle traversing the turnout rails passes across the railjoints e, and enter upon the main rails 58s and 82, the shunt circuitfor electro-magnet B is efiected in the usual way directly between themain rails I81! and I82, through the vehicle wheels and axles. From thetime a train passes rail joints f until it passes out of the centralsection b-c, a continuous shunt cir cuit is thus provided for theelectro-magnet B, and the signals remain in actuated conditionthroughout such passage.

As the leading end of the vehicle enters the section a-b theelectro-magnet A is de-energized, but, in view of the de-energizedcondition of electro-magnet B, the armature of the electro-magnet A ismechanically prevented from falling past the halfway position.The'de-energization of electro-magnet A is, therefore, without effectupon the signals. As the trailing end of the vehicle passes out of thesection bc, the electromagnet B is re-energized, re-closing the contactBI and re-opening the contact B2, thus restoring the signal relays XRand XRI to the initial nonsignaling positions. The re-energization ofelectro-magnet B does not, however, release the lock from the armatureof electro-magnet A, since the latter upon being de-energized appliesthe previously described self-locking feature. Accordingly, thedeparture of the vehicle from the central section serves merely thepurpose of extinguishing the signals.

As the trailing end of the vehicle passes outward beyond the rail joints(1, electro-magnet A is re-energized, and acts to unlock itself andrestore all of the inter-locking elements to the original unlockedcondition.

In the reverse case, where a train entering the section (1-!) passes onto the turnout rails, the operation is the same as in the case ofthrough travel with the exception that the armature magnet C is notde-energized because the vehicle never enters the section c-d. Thesignals are initially actuated at the time the train enters section ab.The signals remain operated until the trailing endof the train passesbeyond the rail joints f, re-energizing electro-magnet B. Electro-magnetA having been re-energized by the departure of the train from thesection a-b,

the re-energization of electro-magnet B restores the signals tonon-signaling position.

Although specific embodiments of the invention have been described, itwill be appreciated that various changes in the form, number andarrangement of the mechanical parts of the apparatus, as well as variouschanges in the electrical relationship between the elements of theimproved control system, may be made within the spirit and scopethereof.

What is claimed is:

1. Relay mechanism comprising, in combination, first, second and thirdoperating coils; a movable armature individual to each of said coils;and interlocking mechanism including means for rendering movement of thearmature for said first coil efiective to control movement of thearmature for said third coil and for rendering movement of the armaturefor said second coil efiective to control movement of the armatures forboth said first and third coils; the armature for said second coil beingfree to move independently of the condition of the armature for saidfirst coil.

2. Relay mechanism comprising, in combination, first, second and thirdoperating coils; a movable armature individual to each of said coils;and mechanical interlocking mechanism engageable with the armatures forsaid coils for rendering movement of the armature of said first coileffective to control movement of the armature of said third coil and forrendering moveof tl'ie armature of said second coil effective to controlmovement of the armatures for both first and third coils; the armatureforsaid second coil being free to move independently of the condition ofthe armature for said first coil.

3. Relay mechanism comprising, in combination, first, second and thirdoperating coils, a movable armature individual to each of said operatingcoils; interlocking mechanism including a member selectively movablefrom a first position to a second position in blocking relation to thearmature for said first coil; and means rendering said armatures forboth said second and third coils effective to cause movement of saidinterlocking member from said first to said second position.

4. Relay mechanism comprising, in combination, first, second and thirdoperating coils; first, second and third movable armatures associatedwith said coils respectively; a first interlocking member movable intoblocking relation to the first armature; a second interlocking membermovable into blocking relation to said third armature; means forsupporting said interlocking members for movement independently of eachother; means rendering said second armature effective to actuate bothsaid interlocking members; and means rendering said first and thirdarmaturcs respectively effective to actuate said second and firstinterlocking members.

5. Relay mechanism comprising, in combination, first, second and thirdoperating coils; first,

second and third movable armatures associated 43 mature; said first andsecond interlocking members being independently movable and both beingdisposed for engagement and movement by said second armature, and saidfirst and second interlocking members being disposed for engagement andmovement respectively by said third and first armatures.

6. Relay mechanism comprising, in combination, first, second and thirdoperating coils; first, second and third movable armatures associatedwith said coils respectively; a first interlocking member engageable andmovable by said first and second armatures for blocking movement of saidthird armature; and a second interlocking member engageable and movableby said second and third armatures for blocking movement of said firstarmature.

JAMES MOORE EVANS. EDMUND J. PHILLIPS.

